The IfcRelConnectsPathElements relationship provides the connectivity information between two elements which have path information. This objectified relationship provides the additional information required to describe the connection between two path based elements that might have single or multiple layers of material. The connection type specifies where at the path-based element a connection is given (at the start, in the middle or at the end). 

The connection is described by a connection geometry, given within the object coordinate systems of the RelatingElement and of the RelatedElement. In case of IfcWallStandardCase as the RelatingElement and RelatedElement the connection geometry is provided by the subtype IfcConnectionCurveGeometry. Both curves indicate the so-called "end cap", i.e. the curve that trims the wall outer edges (being parallel along the wall axis) at the end. 

The next example shows the connection relationship between two instances of IfcWallStandardCase using the IfcRelConnectsPathElements relationship. The ConnectionCurveGeometry defines the CurveOnReleatingElement and CurveOnRelatedElement, both are of type IfcPolyline. 

The next illustration uses the IfcRelConnectsPathElements for a "T" type connection between two instances of IfcWallStandardCase. 

Illustrates using the IfcRelConnectsPathElements for a "L" type connection between two instances of IfcWallStandardCase. 

The two wall axes connect in each case. 

changes 

• IFC4 changes:
  • The data type of RelatingPriorities and RelatedPriorities are restricted to a range o [0..100] to be a normalized ratio measure.
  • Type of the RelatedPriorities attribute changed from "list[0:?] of integer" to "list[0:?] of IfcInteger"
  • Type of the RelatingPriorities attribute changed from "list[0:?] of integer" to "list[0:?] of IfcInteger"